A quick note about the current Atlantic hurricane season. With resect to just the US, we’ve had a fairly low level season, and it is easy to become complacent about this time, but in fact, the risks from Atlantic hurricanes rise about this time of year, so pay attention. Watch for Hermine. More on that below.
We are approximately in the middle of the 2016 Atlantic Hurricane Season, by calendar time. The number of named storms (tropical storms plus hurricanes) predicted for this year is about 14, taking the average of all the predictions made so far, and there have been 7 storms including one currently brewing in the middle of the Atlantic. So, perhaps we are right on track.
But, the first of those seven storms actually happened last year, but after the Hurricane Prediction Center had closed the book on the 2015 season, so Hurricane Alex got dumped into the 2016 season. (It happened in Janurary.) So, we are a bit behind in the total number of named storms.
But, we are not really half way through the hurricane season. It starts on June 1 and ends on November 30th, though as was the case with Alex, individual storms sometimes fail to get the memo. But, more importantly, the peak of the season tends to be around September 10th, and the distribution of Atlantic hurricanes over they year tends to be a bit skewed, with the latter half of the season being more active.
During the period 1851 to 2015 there were 1619 Atlantic tropical storms or hurricanes recorded. 609 of them happened prior to the end of August. The remaining 1010 happened in September, or later, with September and October having most of them.
So, roughly speaking, if we are half way to the predicted 14 named storms now and still in late august, one could guess that we’ll slightly exceed average expectations, but likely fall within the range of those expectations. We’d have to have over 20 or so named storms to raise the eyebrows of most of the predictors.
I get the impression that the percentage of named Atlantic storms that made landfall this year has been on the high side, though there has been no catastrophic landfall to date.
Katrina made landfall in about four days from now (in 2005). Among the deadliest, Sandy (which was a Hurricane that ate another storm and became too big and powerful to maintain its status as a hurricane by landfall, thus dubbed a “super storm” and enigmatically left off most hurricane lists) was later in the year, as were Stan, Jeanne, Mitch, Gordon, Fifi-Oriene, Flora, Jeremie, several other storms. Of recent deadly storms, Katrina was relatively early, and only 1979’s David came close (formed August 25th, fizzled out on September 8th).
So, speaking just of the more powerful storms, that is generally a phenomenon of September or October and now and then November.
Gaston is the currently active named storm. It is likely to form into a hurricane over the weekend, veer right before coming too close to Bermuda, and remain pretty far out in the Atlantic. There are no clear predictions of what it will do by mid week, but it is likely to weaken a bit on Wednesday. Gaston will be in hurricane-hostile territory at that time, so may be it will just go away.
Hermine is the name that would be given to what is now a tropical disturbance, should it form a tropical storm. The changes that it will do so are not small. If Hermine forms up into a reasonable storm, the chances that it would miss already-water-logged Florida are very small. I expect Hermine to be a significant weather event for the southern US.